Pressure venting panel assembly



July 8, 1969 T. J. REILLY PRESSURE VENTING PANEL ASSEMBLY Filed Nov. 7,1967 INVENTOR. 772021205 Jose M Hediy United States Patent US. Cl.49-141 6 Claims ABSTRACT OF THE DISCLOSURE Disclosed herein as apreferred embodiment of the invention is a pressure venting window panelassembly for use in relieving pressures built up in an enclosed buildingstructure as a result, for example, of an explosion.

The assembly includes a panel, pivotably mounted to open and close anopening in the building wall and secured by a magnetic latch. Themagnetic latch permits the assembly to be calibrated to open uponattainment of a predetermined pressure level within the enclosure andcomprises a horse-shoe magnet, and a keeper which magnetically engagesthe magnet to secure the latch in a closed position. The keeper alsoacts as a shunt to maintain the latch at its calibrated value duringperiods when the panel assembly is closed.

Background of the invention Industrial explosions have become an everincreasing problem as the complexity of industry has grown. In order toprotect personnel and save enclosed buildings and equipment fromstructural damage it is desirable, and required by insuranceunderwriters, that pressure relief venting be provided in any enclosurein which an explosion hazard exists. The use of venting is particularlyimportant in those instances where one side or a number of sides of anenclosure are constructed of, or contain areas of glass. If venting canbe accomplished before the glass areas are shattered, the chances ofinjury to personnel are considerably reduced.

In addition, it is often desirable to provide venting in enclosureswhere the exertion of high pressures of less than explosive intensitymay occur, to prevent distortion or structural damage.

'I-Ieretofore, venting has often been accomplished by means of louvers,of either the permanent or pivot-hinge type, which are installed in thewalls of an enclosure. Louvers of any type, however, are unsatisfactoryin situations where the enclosure must contain a certain amount ofinternal pressure such as in forced air drying ovens and in rooms havingforced ventilation.

Alternatively, panels which are secured by mechanical latches designedto open under pressure have been used to vent enclosed structures. Themechanical type latch, however, has proven to be expensive and difiicultto install; more importantly, mechanical latches are extremely difficultto calibrate for release at redetermined pressure levels. In addition,any calibration effected on a mechanical latch is subject to significantchange in time as a result of mechanical distortion, oxidation andcorrosion.

Accordingly, representative objects of the present invention are toprovide a means for the pressure relief venting of enclosed structuressuch as industrial buildings, drying ovens, storage tanks, ducts and thelike, which is readily calibrated to open at a predetermined pressurelevel, and which is reliable, inexpensive and easy to install.

Other objects of the invention will in part be obvious and will in partappear hereinafter.

The invention accordingly comprises the features of construction,combinations of elements, and arrangement 3,453,777 Patented July 8,1969 of parts which will be exemplified in the constructions hereinafterset forth, and the scope of the invention will be indicated in theclaims.

Summary of the invention The present invention relates to a pressureventing panel assembly for enclosed structures, having a mag netic latchfor accurate calibration and reliable operation.

Referring to FIGURE 1, the panel assembly comprises a panel 10, whichmay be a glazed window as shown, pivotably mounted in a frame 12surrounding an opening 14 in the wall 16 of an enclosure.

A magnetic latch 18, comprising a magnetically attractive keeper 20mounted on panel 10 and a permanent magnet 22 mounted to frame 12,secures the panel of the invention in a closed position as shown at thetop of FIGURE 1. Latch 18 is calibrated, as is more fully describedherein, so that keeper 20 will disengage from magnet 22 upon theapplication of sufiicient pressure P to the surface 24 of panel 10, aswhen. an explosion or high pressure condition occurs within theenclosure. The disengagement of keeper 20 from magnet 22 allows panel 10to open as shown at the bottom of FIGURE 1, thus forming a vent for therelease of excess pressure.

The calibration of latch 18 should be such that venting occurs at apressure level below the rupture pressure of the walls 16 of theenclosure to prevent structural damage thereto. In addition, whereglazed windows are used as panels as shown in FIGURE 1, latch 18 shouldbe calibrated to disengage at a pressure below the breaking stress ofthe glass to minimize the danger to personnel. The strengths of commontypes of glass can be determined from sources such as Breaking Stress ofGlass at Ambient and Low Temperatures, K. E. Anderson, H. W. Tyler andR. V. Smith, Design News, Oct. 12, 1959.

Brief description of the drawings For a fuller understanding of thenature and objects of the invention, reference should be had to thefollowing detailed description taken in connection with the accompanyingdrawing in which:

FIGURE 1 is a front perspective view of two pressure venting windowpanels in accordance with the invention, the upper panel showing theclosed and the lower panel showing the open position thereof.

FIGURE 2 is an enlarged sectional view taken along line 2-2 of FIGURE 1showing, in dashed lines, the panel of the invention in open andpartially open positions.

FIGURE 3 is a greatly enlarged partial sectional view taken along line3-3 of FIGURE 1.

Similar reference characters refer to similar parts throughout theseveral views of the drawing.

Description 0 the preferred embodiments Referring now to FIGURE 1, thepressure venting panel assembly of the invention comprises a panel 10which may be a solid sheet of suitable metallic, plastic or similarmaterial; preferably, however, and in particular where the panelassembly is used in habitated building structures such as factories,research labs and the like, panel 10 comprises a glazed window having aglass sheet 26 suitably mounted in a casement 28 and secured therein byputty 30 or a similar glazing material (FIGURE 3). Casement 28 isprovided with an abutment 32, and channel strips 34 are forcefittedbetween abutment 32, and glass sheet 26 to reinforce the putty 30 insecuring glass sheet 26.

Panel 10 is pivotably mounted either singly, or in groups as shown inFIGURE 1, in a frame 12 surrounding an opening 14 in the wall 16 of anenclosed structure.

3 Frame 12 may be formed of extruded metal, wood or similar suitablematerials and the configuration thereof should conform to theconfiguration of casement 28 so that the two can mesh to substantiallyseal opening 14 when panel is closed. As shown in FIGURE 3, when thepanel assembly is closed an upstanding lip 36 running along the outsideedge of frame 12 is abutted by the outside dependent flange 38 ofcasement 28, and the upstanding flange 40 along the inside edge of frame12 is abutted by the inside edge 42 of casement 28 to seal the openingand provide an air space 44. Where further sealing is desired, resilientgaskets may be secured to one or both of the mating surfaces of lip 36and flange 38, and/or edge 42 and flange 40.

The pivotable mounting of panel 10 is effected by means of a pair ofpivot pins 46 (FIGURE 1) protruding at one end from bearing blocks 48 ateach end of the top surface 50 of casement 28. The other end of eachpivot pin 46 is received in a sliding block 52 loosely mounted in aslide channel 54 on the inside end surface 56 of frame 12. Pivot pin 46may be pivotably mounted in either bearing block 48 or slide block 52and fixed in the opposite member, however, it is preferably pivotablymounted in both block 48 and 52 to minimize the chances of binding.Thus, as illustrated by FIGURE 2, panel 10 may be pivoted between openand closed positions as a result of the sliding action of block 52 inchannel 54 and the pivoting action of pin 46. A stop 58 is also providedin each channel 54 both to limit the sliding movement of block 52 andthus limit the outward movement of panel 10 to a desired degree, and toprevent block 52 from leaving channel 54.

In applications where the panel assembly of the invention must withstandand vent pressures due to explosion, panel 10 should preferably remainopen after an initial explosion. This is important since secondaryexplosions following closely behind the initial explosion may otherwiseoccur as panel 10 is returning to its closed position, and the combinedforce of the secondary explosion outward, and the momentum of panel 10inward may cause structural damage to the panel or shatter the glass 26.Accordingly, a linkage arm 60 is pivotably fastened at one end 62 toeach side of casement 28 below pivot pin 46. The other end 64 of arm 60is pivotably attached to a stud assembly 66 projecting from the innersurface 56 of frame 12, below and in line with channel 54. The pivotalconnections at 62 and 64 should be loosely made to minimize friction sothat panel 10 will readily swing open upon application of apredetermined pressure force as shown in FIGURE 2. Arm 60 then serves tomaintain panel 10 in the open position for the purpose of ventingpressures due to secondary explosions. Arm 60 also serves to reinforcepanel 10 against lateral movement and provide a rigid panel assembly.

The panel assembly of the invention is provided with a magnetic latch 18so that it may readily be calibrated to open upon application of apredetermined pressure against surface 24 of panel 10. Preferably, akeeper 20 magnetically attractive material such as iron, nickel or amagnetic alloy is fastened to the outwardly moving side 68 of casement28 at the midpoint thereof by a screw 70. However, where casement 28 isof magnetically attractive material, it will function as a keeper andthe separate keeper 20 may be dispensed with. A bracket 72 is fastenedto flange 40 of frame 12 by screws '74, in alignment with keeper 20. Apermenent magnet 76 is preferably mounted to bracket 72 by means of abolt 78, the head 80 of which is recessed within a slot 82 in the faceof magnet 76 to permit direct contact between magnet 76 and keeper 20;bolt 78 is secured by a nut 84. Slot 82 extends completely through thesides of magnet 76 so that it, in effect, becomes a horse-shoe typehaving legs 76a and 76b of opposite polarity as shown in FIGURE 3.

A pull chain 86 is provided on latch 18 to facilitate the closing ofpanel 10. Chain 86 is fastened to side 68 of casement 28 adjacent keeper20 and a loose end extends through an opening 88 in bracket 72 adjacentmagnet 22; a pull ring 90 is provided on the loose end for the operatorsconvenience.

In addition to being readily calibrated, magnetic latch 18 will maintainits magnetic attractive force constant over extended periods of time. Asshown in FIGURE 3, when panel 10 is in its normal closed position,keeper 20 acts as a shunt between the opposite poles of legs 76a and7612. As will be recognized by those skilled in the art, the provisionof a shunt will maintain magnet 76 at a substantially constant strength,thus providing a reliable magnetic latch which will open at itscalibrated pressure level even after long periods of non-use.

While only a single magnetic latch comprising one magnet and one keeperhas been shown in a preferred embodiment, it will be understood that thepanel assembly of the invention may include two or more such magneticlatches of similar or varying geometry and magnetic force wheredesirable for a particular application.

It will thus be seen that the objects set forth above, among those madeapparent from the preceding description, are efiiciently attained and,since certain changes may be made in the above constructions withoutdeparting from the scope of the invention, it is intended that allmatter contained in the above description or shown in the accompanyingdrawing shall be interpreted as illustrative and not in a limitingsense.

It is also to be understood that the following claims are intended tocover all of the generic and specific features of the invention hereindescribed, and all statements of the scope of the invention, which as amatter of language, might be said to fall therebetween.

Having described my invention, What I claim as new and desire to secureby Letters Patent is:

1. A pressure venting panel assembly for an enclosure comprising, incombination:

(A) a panel (1) pivotably supported in an opening in said enclosure, and

(2) pivotable between open and closed positions,

(B) magnetic latch means calibrated to disengage upon application of apredetermined pressure below the rupture pressure of said enclosure andcomprising (1) means forming a keeper of magnetically attractivematerial, and

(2) at least one magnet having legs of opposite polarity extended towardsaid keeper,

(3) said keeper and magnet each being on one of two adjacent surfaces ofsaid panel and enclosure in position to magnetically engage and holdsaid panel in said closed position, whereby said keeper acts as a shuntto maintain said magnetic latch means at its calibrated value when saidpanel is closed, and

(C) means for maintaining said panel in an open position afterapplication of pressure sufficient to disengage said magnetic latchmeans.

2. An assembly as defined in claim 1 wherein said panel comprises awindow and wherein said magnetic latch means is calibrated to disengageupon application of a pressure below the breaking stress of the glass insaid window.

3. A pressure venting panel assembly for an enclosed buildingcomprising, in combination:

(A) a frame (1) mounted in an opening in said building,

(B) a panel (1) pivotably mounted in said frame and (2) pivotablebetween an open position wherein said opening is uncovered and a closedposition wherein said opening is substantially sealed,

(C) a magnetic latch comprising a magnetically at- 5 6 tractive keeper,and a permanent magnet having legs secured to said panel to form saidkeeper and a permaof opposite polarity extended toward said keeper, nentmagnet of the horse-shoe type mounted to said (1) each supported on oneof two adjacent surframe on a bracket in alignment with said keeper whenfaces of said panel and frame, said panel is closed.

(2) said keeper being magnetically engaged 6. An assembly as defined inclaim 5 and including a across both said legs of said magnet when said 5pull chain for closing said panel secured to said panel panel is closedto hold said panel in said closed adjacent said keeper and extendingloosely through an position and to provide a magnetic shunt, and openingin said bracket. (3) said latch being calibrated to disengage and allowsaid panel to open upon application of a 10 References Citedpredetermined pressure to said panel, and UNITED STATES PATENTS (D)means maintaining said panel in an open position t after application ofpressure sufiicient to disengage gg igg 11//19632 gZ P 2 5 said magneticlatch comprising a pair of linkage 1351 1 3/3 A 25;: T9- 31"*X arms,each pivotably connected at one end to one 15 side of said panel and atthe other end to said frame adjacent the corresponding side of saidpanel. FOREIGN T Z 4. An assembly as defined in claim 3 wherein said629,903 9/1949 Great Britain. panel is a window and wherein saidmagnetic latch is calibrated to disengage below the breaking stress ofthe 20 KENNETH DOWNEY=Prlmary Exammerglass in said window.

5. An assembly as defined in claim 3 wherein said magnetic latchcomprises a magnetically attractive plate 49---3l, 252; 52-1; 292-2515

